The bottom side of a typical semiconductor package contains conductive traces and protruding terminals in order to make contacts with printed circuit boards (PCB). The protruding terminals and conductive traces are exposed and likely to be contaminated. The contamination can cause electrical shorts between exposed traces.
FIG. 1 illustrates a typical semiconductor package 100 with exposed traces. The bottom view 102 of the semiconductor package 100 shows exposed traces 106 and protruding terminals 108. Cross sectional views 104A and 104B show the views along lines A-A′ and B-B′ of the bottom view 102 respectively. View 104L shows a wire bond version of the cross sectional views 104A and 104B. View 104R shows a flip chip version of the cross sectional views 104A and 104B. As shown in the views 104L and 104R, both traces 106 and protruding terminals 108 are exposed and can be contaminated in a manner to cause shorts.